Not exact matches
In the meantime,
there's a link in the ETA part of the above post which goes to The Digital Reader where you can find a link to Calibre plugin which works with the Kobo Desktop app to convert
kepub books into epub.
ePub3 would suggest it's a problem not within Kobo's control («hey, sorry,
there's nothing we can do»)-- whereas
KePub is TOTALLY within their control.
It seemed to me Adobe, who is providing a lot of the resellers including Kobo, didn't support EPUB 3 with DRM, which would mean that actually
there is no way to support it, hence the «
kepub only».
kepub and those go away OR
there's a patch for the Kobo OS to get rid of them with.